Since the 1950s, some portions of Antarctica have cooled (as denoted in faint blue tones), but many areas, including West Antarctica, have warmed substantially (red tones). The stronger the tone, the larger the warming or cooling.

At left is Peru’s Qori Kalis glacier in 1978, when it was still healthy. At right is the much-reduced glacier in 2000. A lake of meltwater now occupies what 22 years earlier had been a deep field of flowing ice.

NASA has scheduled the last servicing mission for the orbiting Hubble Space Telescope. In May, astronauts will attempt to repair instruments in an effort to keep the space craft up and running until at least 2014.

After spending weeks and months swimming in the open sea, mature Atlantic bluefin tuna return to the area where they first hatched. They do so in order to spawn, or reproduce. These bluefin tuna are divided into two groups: western Atlantic bluefins and eastern Atlantic bluefins. When it’s time to mate, the mature westerners head toward the Gulf of Mexico, while the mature easterners return to the Mediterranean.